See the video here: Make sure to check it out at the 4:22 min mark for when the rocket and spacecraft separate.
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The Cygnus spacecraft is an unmanned resupply spacecraft being developed by Orbital Sciences Corporation as part of NASA's Commercial Orbital Transportation Services(COTS) developmental program. It will be launched by Orbital's Antares rocket and is designed to transport supplies to the International Space Station (ISS) following the retirement of the American Space Shuttle. Since August 2000 unmanned ISS resupply missions have been regularly flown by Russian Progress spacecraft, as well as by the EuropeanAutomated Transfer Vehicle, the Japanese H-II Transfer Vehicle, and the SpaceX Dragon. With the Cygnus spacecraft, NASA seeks to increase its partnerships with domestic commercial aviation and aeronautics industry.